Feb 4,
2011 - Testing facilities. A vacuum chamber. Finally it is working –
one cooking pot from a kitchen (strong enough), a used freezer's compressor,
couple feet of tubing, a water drain PVC pipe, a manometer from an automotive
shop and this is a result. Yes
– important parts: rubber gasket (1.7mm), and two acrylic glass sheet. Previous
problems solved – different sealant tapes works “badly”; a stainless still
cooking pot with thin sides is not strong enough to withstand vacuum pressure
and will cave inward with a big bang; one acrylic glass sheet also produce funny
sounds with all structure collapsed.

A vacuum chamber needs to be
big enough to accommodate an antenna
with an antenna box, this is 60 cm in length (on top of a box). This is why a
PVC pipe comes to equation. Pipe's sides has to be sanded with a rough
sandpaper and then with a fine sandpaper. Sanding better to do on a flat
surface. The imperfection of a sending will be covered by a rubber gasket – it
requires four – one btw a cooking pot and a first acrylic sheet, second btw a
same size second acrylic sheet, and a last gasket btw an acrylic sheet and a PVC
pipe, on top of the pipe another gasket seals contact surface to a small piece
of an acrylic glass. In that (top) sheet, small hole accommodates a simple
connector inserted into tubing to a freezer's compressor. Used compressors also
has a puncture hole, this will be control valve – any small piece of sealant
tape applied to this hole will close or open “valve”. Three gaskets made as
concentric cuts from one piece of rubber. Additional on top is the same size as
a small one. Three gaskets inserted btw pot and two acrylic glasses actually
redistribute pressure. Tubing needs be long – not only for convenience, but for
placing air filters.

Vacuum chamber's manometer shows something around
-72cm, but it is not accurate. Final performance will be available after
assembly of all sensors including air-pressure.

Without PVC
pipe vacuum chamber will be able to accommodate any small parts of
a vehicle and probe. One piece of an acrylic glass is enough to withstand
pressure and will be served as a window for solar panels tests. But most
important for now - it is possible to manufacture composite elements of a
vehicle. Bubbles in epoxy does not allow to make carbon fiber to be strong
enough.